Carbon black furnaces



1953 E.`B. MILLER 2,649,360

CARBON BLACK FURNACES Filed Jan. 24, 1949 3 Sheets-Sheet 1 ywamlmFam/ear B. Msa

ATTOR N EYS Aug. 18, 1953 EJB. MILLER CARBON BLACK FURNACES 3Sheets-Sheet 2 Filed Jan. 24, 1949 6545 FkoM Five-years&

JNVENTOR. ERNEST B. MILLER Aug. 18, 1953 EQB. MILLER 5 3 CARBON BLACKFURNACES Filed Jan. 24, 1949 3 Sheets-Sheet 3 art/um Fane-.sr B. MILLERTTORNEYS Patented Aug. 18, 1953 CARBON BLACK FURNACES Ernest B. Miller,Houston, Tex., assignor to J efterson Lake Sulphur Company, New Orleans,La., a corporation of New Jersey Application January 24, 1949, SerialNo. 72,425

3 Claims.

This invention relates to a furnace for making carbon black by thepartial combustion of hydrocarbon gases.

One of the objects is to provide a furnace having a central reactionchamber into which air is admitted on opposite sides through a series ofslots or openings to cause some of the gas to burn and form flamesdirected downwardly along the side walls of the chamber throughout itsworking area.

Another object of the invention is to provide a furnace of thedown-draft type having air slots or openings in the side walls of acentral reaction chamber of such total cross sectonal area relative tothe cross sectional area of the chamber as to insure substantiallyuniform distribution of air throughout the Working height of thechamber. The idea is to provide a furnace of this type having a maximumcapacity for producing carbon black of small particle size.

Other aims and advantages of the invention will appear in thespecification when considered in connection with the accompanyingdrawings, wherein:

Fig. 1 is a vertical sectional View of a furnace embodying theinvention;

Fig. 2 is a vertical sectional View, taken on the line 2-2 of Fig. 1;

Fg. 3 is a perspective view of one form of refraction tile or brick usedin building the furnace; s

Fig. 4 is a fragmentary sectional View of a furnace wall; and

Figs. 5 and 6 are fragmentary face views taken on opposite sides of aslotted urnace wall.

Referring more particularly to the drawings, the furnace is illustratedas being of the downdraft type having a single reaction chamber.However, it will be understood that such furnaces have several suchchambers in a single unit.

In this instance, the urnace is illustrated as being rectangular incross section, having side walls ID, end walls l l, a top wall !2, and abottom wall I3, all made of refractory material. A pair of perforatedvertical partitions 14, made of refractory bricks, divides the furnaceinto a narrow central reaction chamber IE and two air inlet chambers son its opposite sides.

Preheated hydrocarbon gas, such as methane, is introduced in the upperend of the reaction chamber through a gas Conduit ll and perforatedmanifold !8, shown as being embedded in the upper wall I 2. Preheatedair to support partial combustion of the gas is introduced in the bottomportions of the air chambers through conduits !9. The reaction chamberhas an outlet fiue 25 connected to an outlet Conduit ZI leading to acarbon collector.

:In accordance with this invention, the partitions I 4 forming the sidewalls of the reaction chamber are provided with a multiplicity of slotsor perforations 22 dispersed throughout a major portion of their heightand arranged in staggered vertical rows. sectional area of these slotsis so proportioned to the horizontal cross sectional area of thereaction chamber as to provide for substantially uniform flow of airinto the reaction chamber throughout its height. Actual operation hasdemonstrated that the ratio should be between on to four and one to tento produce best results. The slots are preferably wedge-shaped or flaredhorizontally from the air chambers into the the reaction chamber toprovide for wide, slow-moving jets of air entering the reaction chamber,so that the air jets will not penetrate the gas stream to a substantialdepth. The idea is to provide jet flames which wipe the entire surfaceof the inside walls of the reaction chamber throughout its working areaor height. This prevents thermatomic carbon from being de posited on thewalls and rapidly clogging up the reaction chamber.

'Referring to Figs. 3 and 4, the slots 22 are shown as being formedacross the upper faces of interlocking refractory bricks 23. Threeflared slots are shown in each brick, one at the center and one on eachside, so that they will be arranged in staggered vertical rows when thebricks are laid in the usual break-joint fashion to form the walls, asshown in Figs. 5 and 6. The slots in alternate horizontal rows of bricksare vertically aligned, so that the slots in adjacent vertical rows arestaggered with respect to each other. Each slot has a very small inletorifice and a wide outlet orifice. Obviously, the efl'ectiv crosssectional area of the slots, which determines the rate of flow of airthrough them, is measured across the small inlet orifices. Thehorizontal space between the orifices is about half the width of theorifices. The air jets thus provide for wide, downwardly directed flameswhich wipe against and cover the inside walls of the reaction chamber.

The air flow in the air chambers is directed upwardly or opposite to thedownward flow of the gas in the reaction chamber so that the air streamswill acquire their maximum static pressure at the upper ends of thechambers and thus cause the air jets to flow into the reaction cham- Thetotal, effective cross- 4 ber against the pressure of the gas stream.The chambers; said refractory walls of the reaetion pressure of the airis maintained only slightly chamber having a multiplieity of smalltransgreater than that of the gas. If wide slots are verse Slotsextending therethrough and uhiforn provided and the air is introduced atthe top of ly distributed throughout the working area er" the the airchambers, gas will escape through thei .5 reaction chamber to permit theintrodue 3 of Slots and cause combustion to take place in the air fromthe air chambers to the reaction chamupper portions of the air chambersand thereby ber on opposite sides of the stream of gas passing greatlyreduee the production Capacity of the therethrugh;"'Saiti` slots 'barranged in subfurnace. startially horizontal rows'v'rith the slets ineach The Construction and arr m a e such row staggered with respect tothe slots in the aslthat the air introduced into the bottom portions'jacent rows and each slot having a very small of the air chambers at apressure exceeding the air inlet orifice leading from the air chamberand pressure of the gas supplied to the reaction chambeing horizontallyfiared. toward the reaction ber is caused to flow through theslotsubst'aII- chamb'ef to "permit the air to flow in relatively tiallyat a uniform rate throughoutthewoflirig wil str'eajiris""=into"= saidreactioh chamhe 'n area of the reaction chamber. The uniform disthereby'eausea'me's to Wipe the en re :le tributicn of the small slotsand theirareas'are surface-ofeachrefractory Wall throughout theimportant factors in maintaing a substantially Working height of thereaetion chamber; and the uniform, effective pressure difference'between total cross sectional area of the small of said the air and thegas streans. Slots in both walls being between about ehe- In a furnae ofthis type;'-the width of the foirth andone-trth f-th horizontalcrcss'seo reaction: chamber or thickness of the'gas stream tion area''of th e fit cha b should not be more than-'fiv' orsix-'ihches when 2 Ina carbon b k ur st the lieight is three'to twelve :feeta'nd'the gascaclaim -1 wh'erein th' -refractory-w is gj or oil v por p r n t -Th jis preheated to fiared 'slo'ts for m'edi-n thiru erfaces.

a temperature-Of 21100111378007?. o and 3. Ina earbon-' black 'furnaceas seterth in about 250 cubi' feet of airer minute is introclairnl,Wherein-' the-wiele-rifiees'of the siots enduced at a temperature"between 19%? and tering the reaotion cha mb'er are substantialiy 1200 FTh l tire at the" o'utlet of the rectangular with the bottom wallsthereo inc lihetl reaction chamber is mai'tained at about 2300 F.downwardly to dirct' th air=streams clownward- The "temperatur iskept"`substantially uniform ly t a thv'ifift am o above the dissocationtemperature 'of the gas thr'ughout'th'e workihg height of 'the reactionERNES B, M nga oha'mb'e'r.` V-

obv'iousy; th ifv'entioh is not res'tricted to the References' Olta& meof "ths patent partiular 'embodi'm'eht 'threofherein 'shown and UNITEDSTA IES :PA'IENTS described. Number Na'in'e Date What s claimdis: I1592574: szarvasy't July 13, 1926 1. In a' carbon'blackiurnace of thedown-draft 40 2362353 w Dec 1 9 5 type having gjeneralit" reetang-lar'vertical side 2347336 I 1941 and end walls; a pair of 'spaedrefraet'ory walls 21436332 1943 within th"furnace` parallLWitHth sidewalis 4 3 Wi'eandt Apr' 27 1943 extending 'from' top to bottoi'n ahd.`defining a i narrow rea'ction' chamber 'not more 'than about FOREIGNPATENTS six inchs Wide 'and-'anak chamber Un each side' Number countr siDate between them 'and' said side walls; a gas mani 196, 972 Gra'tBriti- May 19237 fold in the upper end of said reaetioh' chamber airinlet eonduits in thelowe'r' end's of 'said 'air

1. IN A CARBON BLACK FURNACE OF THE DOWN-DRAFT TYPE HAVING GENERALLYRECTANGULAR VERTICAL SIDE AND END WALLS; A PAIR OF SPACED REFRACTORYWALLS WITHIN THE FURNACE PARALLEL WITH THE SIDE WALLS EXTENDING FROM TOPTO BOTTOM AND DEFINING A NARROW REACTION CHAMBER NOT MORE THAN ABOUT SIXINCHES WIDE AND AN AIR CHAMBER ON EACH SIDE BETWEEN THEM AND SAID SIDEWALLS; A GAS MANIFOLD IN THE UPPER END OF SAID REACTION CHAMBER; AIRINLET CONDUITS IN THE LOWER ENDS OF SAID AIR CHAMBERS; SAID REFRACTORYWALLS OF THE REACTION CHAMBER HAVING A MULTIPLICITY OF SMALLTRANSVERSELY SLOTS EXTENDING THERETHROUGH AND UNIFORMLY DISTRIBUTEDTHROUGHOUT THE WORKING AREA OF THE REACTION CHAMBER TO PERMIT THEINTRODUCTION OF AIR FROM THE AIR CHAMBERS TO THE REACTION CHAMBER ONOPPOSITE SIDES OF THE STREAM OF GAS PASSING THERETHROUGH; SAID SLOTSBEING ARRANGED IN SUBSTANTIALLY HORIZONTAL ROWS WITH THE SLOTS IN EACHROW STAGGERED WITH RESPECT TO THE SLOTS IN THE ADJACENT ROWS AND EACHSLOT HAVING A VERY SMALL AIR INLET ORIFICE LEADING FROM THE AIR CHAMBERAND BEING HORIZONTALLY FLARED TOWARD THE REACTION CHAMBER TO PERMIT THEAIR TO FLOW IN RELATIVELY WIDE STREAMS INTO SAID REACTION CHAMBER ANDTHEREBY CAUSE FLAMES TO WIPE THE ENTIRE INSIDE SURFACE OF EACHREFRACTORY WALL THROUGHOUT THE WORKING HEIGHT OF THE REACTION CHAMBER;AND THE TOTAL CROSS SECTIONAL AREA OF THE SMALL ENDS OF SAID SLOTS INBOTH WALLS BEING BETWEEN ABOUT ONEFOURTH AND ONE-TENTH OF THE HORIZONTALCROSS SECTIONAL AREA OF THE REACTION CHAMBER.